1. Field of the Invention
This invention relates generally to systems and methods that use wireless physiological monitoring and more particularly to respiratory monitoring. People need to breathe to stay alive. The medical term “apnea” refers to temporary cessation of respiration or breathing or an irregular breathing pattern. Some people do not have normal breathing, for example when they sleep, and monitoring breathing can be helpful to diagnose patients.
One conventional approach to diagnosis of sleep disorders has been to require the patient to participate in a “sleep study.” The patient is outfitted with an array of sensors attached to the surface of the body to monitor the patient's respiration, pulse, and blood oxygen saturation. A strip chart recorder can trace the sensor signals on paper for later analysis by a health care professional.
Conventional sleep studies may have several shortcomings in at least some instances. The complexity and expense of the required equipment can dictate that sleep studies be conducted in a clinic setting, i.e., a hospital or sleep laboratory. This can significantly increase the costs involved. In at least some instances, the patient may find it difficult to sleep in a strange setting, particularly while wearing sensors tethered by wires to a recorder, such as a strip chart recorder. In some instances, respiration may be measured by requiring the patient to wear sensor devices applied to the face and body, which can especially uncomfortable to wear while trying to sleep.
With newer technology, sleep studies can be done in the home, but this may still involve attaching various sensor devices and wires to the body surface. These tests may be single night events, and in at least some instances may be too complex and expensive to be practical in monitoring treatment efficacy and patient compliance over extended periods of time, such as days, weeks, or months.
One common treatment of sleep apnea may involve blowing air under pressure into the upper airway via a mask strapped to the face, which may be uncomfortable in at least some instances. Continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP) are the treatment modalities that have been delivered by masks. Even though sleep apnea can be corrected with CPAP and BiPAP, both may have excessively high non-compliance rates due patient discomfort in at least some instances.
The apnea condition has become associated in recent years with the sudden infant death syndrome, or SIDS, in which an apparently healthy infant dies of an unexplained cause. Although much research has been done, many infants still die of this disease.
Cough can be a complaint of COPD (chronic obstructive pulmonary disease) patients (and other patients) that may impact sleep and can significantly impact quality of life at a functional, in at least some instances.
Therefore, a need exists for improved sleep monitoring and management of sleep disordered breathing, such as a respiration monitoring system for diagnosis of sleep disorders that is suitable for use outside of clinical settings, and which minimizes patient discomfort and can be used on patients of all ages from infant to adult. Ideally such, systems would be less obtrusive to the patient than current, systems, and provide monitoring that can be used to improve patient therapy.
2. Description of the Background Art
The following U.S. Patents and Publications may describe relevant background art: U.S. Pat. Nos. 4,121,573; 4,955,381; 4,981,139; 5,080,099; 5,353,793; 5,511,553; 5,544,661; 5,558,638; 5,724,025; 5,772,586; 5,862,802; 6,047,203; 6,117,077; 6,129,744; 6,225,901; 6,385,473; 6,416,471; 6,454,707; 6,494,829; 6,527,711; 6,527,729; 6,551,252; 6,595,927; 6,595,929; 6,605,038; 6,641,542; 6,645,153; 6,821,249; 6,980,851; 7,020,508; 7,041,062; 7,054,679; 7,153,262; 7,206,630; 7,297,119; 2003/0092975; 2005/0113703; 2005/0131288; 2005/0137464; 2005/0277841; 2005/0277842; 2006/0010090; 2006/0031102; 2006/0089679; 2006/122474; 2006/0155183; 2006/0161205; 2006/0173257; 2006/0173269; 2006/0195144; 2006/0224051; 2006/0224072; 2006/0264730; 2007/0021678; 2007/0038038; 2007/0073132; 2007/0123756; 2007/0129643; 2007/0150008; and 2007/0255531.